PB2180: TREATMENT CHALLENGES OF COEXISTING MYELOID AND LYMPHOID NEOPLASM- A CASE REPORT
Authors: Mihailo Smiljanic, Danijela Lekovic, Maja Perunicic Jovanovic, Vojin Vukovic, Darko Antic, Biljana Mihaljevic
Journal: HemaSphere (2023)

Topic: 15. Myeloproliferative neoplasms - Biology & Translational Research Background: Coexistence of myeloid and lymphoid neoplasm is extremely rare. Previous reports indicates clonal independence of myeloproliferative neoplasm (MPN) and chronic lymphocytic leukemia (CLL) occurrence. When such rare coexistence occur, in most reported cases lymphoid neoplasm has an indolent clinical course as well as low-risk biological profile. Aims: Presenting treatment challenges in very rare case of our patient initially diagnosed with essential thrombocythemia (ET) and free years afterwards with CLL. Methods: We diagnosed ET after bone marrow biopsy, clinical, and laboratory findings, cytogenetic analyses and JAK2V617F mutation status. Regular check-ups after Hydroxyurea was introduced was maintained. Subsequent CLL was diagnosed following clinical, radiography (computerized tomography of chest, abdomen and pelvis) findings as well as immunophenotyping of peripheral lymphocytes by flow cytometry. Chemotherapy effect of CLL treatment was confirmed via physical finding, laboratory, and radiography post-treatment findings. Results: Our female patient, aged 57, was initially diagnosed with ET with normal karyotype, as well as confirmed JAK2V617F mutation in March 2015. Initial treatment with Hydroxyurea (HU) 2x500mg per day was introduced, after assessment of cerebrovascular risk factors presence, as well as leukocytosis degree on presentation. Three years later, triggered by progressive leukocytosis (26.4x109/L) with lymphocytosis (91%), hematological reevaluation was performed with confirmation of CLL, staged as II CS (Rai), with immunophenotype analysis revealing CLL score 5, CD38-. After further clinical assessment, HU therapy continued with CLL on “watch and wait”. In February 2020, bone marrow biopsy was performed, as leukocytosis progression was confirmed, reaching as much as 60x109/l, pathohistological finding revealed 60% lymphocytes infiltration. Further diagnostics showed normal FISH finding, cytogenetic analysis detected normal karyotype. Due to regular platelet count maintenance, HU treatment was discontinued. In less than six months period leukocytes “doubling time” was detected, with leukocytes count peak of 155x109/L. Also progressive lymphadenopathy was confirmed with splenomegaly that was previously undetected. At this point CLL treatment with Obinutuzumab-Chlormabucil was introduced, six cycles in total, with complete remission effect. Less than a year later, HU was re-introduced due to progressive thrombocytosis, whereas regular leukocytes count and leukocytes formula maintained. Summary/Conclusion: Patient with MPN was diagnosed three years later with CLL that, following two year period of “watch and wait”, demanded intensive chemotherapy. Therefore, in our experience, regular follow-up of patients with myeloid and lymphoid neoplasms coexistence is necessary, primarily because of carrying out treatment of more active malignancy, in accordance to current findings. Because of increased myelosuppressive effect risk if combined treatment is performed, successive therapy is advised. Keywords: Thrombocythemia